1 Field of the Invention
The present invention relates to a fireproof structure that protects the walls of water pipes installed in incinerators, boilers and the like for cooling and heat exchange from the high temperature gas environment therein. In particular, it relates to a protective fireproof structure and method of its installation which can be implemented on water pipe walls having curves or bends.
2. Description of the Related Art
Water pipes are installed inside of garbage incinerators, boilers and the like to cool the high temperature gas environment or perform heat exchange, and those water pipes have been protected from not only the high temperature gas environment, but the abrasion from flying ash and corrosion by the installation of fireproof tiles or fireproof castable structures around the incinerator/furnace walls.
Such walls of water pipes have been, for example, installed in stoker type incinerators 50 on the inside of the incinerator walls 56 as shown in FIG. 9. The stoker type incinerator 50 is comprised of trash inlet opening 51, grate 53, ash removal opening 54, air supply duct 55, and free board 52. Boiler water pipes are installed on incinerator wall 56 in order to recover the waste heat generated by burning.
As shown in FIG. 8, installed over the entire surface of the inner wall of the incinerator 56 is an array of boiler pipes 10, which comprise water pipe wall 26. That surface is covered by refractory tiles 25, refractory block, refractory castable or other fireproof material.
However, the combustion chambers of incinerators such as stoker type incinerators 50, or those in boilers and the like, have a number of openings such as air duct 55, an opening (manhole) for egress of maintenance workers to perform maintenance, and openings for the insertion of monitoring instruments such as a thermometer. The foregoing water pipes 10 must be installed to detour around such openings. Accordingly, there are a number of areas where water pipes 10 have a plurality of bends and lack a regularly arrayed structure, such as around a thermometer seat 24, manhole 22, monitoring instrument insertion openings, and air ducts.
In the prior art, a refractory castable or specially shaped refractory tiles were installed in these areas, around openings and the like, where the water pipes assumed a complex shape.
However, when installing fireproofing such as the foregoing refractory tiles, which have a fixed shape, costs would rise due to the need to manufacture several different types of refractory to conform to the bends around the individual openings. Further, due to the need for these individual, complexly shaped fireproofing materials, both their manufacture and installation were extremely difficult.
On the other hand, the refractory castable, being amorphous, can be easily installed on site. However, the precision with which it was installed was apt to vary depending upon the skill of each worker, and its longevity was inferior to that of the fixed-shape refractories, which were pressed and fired in a factory.
In particular, when incineration was performed in a higher temperature zone than commonly used incinerators, because it was necessary for the fireproof structure to protect the entire surface, including the area of pipe bends 21, from the high temperatures, fireproof bricks or the like were conventionally installed along the entire wall of the incinerator in the areas around the foregoing free board 52 and grate 53 and around the above described areas near openings where the water pipes were bent. This resulted in increasing the surface area where the fireproof structure exhibited a complex shape, and it made the foregoing refractory tiles very costly. Further, since the longevity of the foregoing refractory castable is unstable, there was a high probability that the water pipes would become exposed and damaged.